Today, I continue to highlight a monster found in Rappan Athuk. There are 3 days left on Frog God's Kickstarter. I am thinking of moving Monster Monday over to the Silver Bulette blog, and focusing entirely on megadungeons here. I will make the decision in the next week or so.
In the meantime, today's Monster Monday features the basilisk. There is a section in Rappan Athuk called (gasp!) Basilisk Caverns. Wandering monsters in this area have a 50% chance of being basilisks. In the S&W version, all movement is halved, due to rough terrain. Saves must be made for moving faster, with failures meaning the character has fallen, taking 1d3 damage.
Similar to the cockatrice, the basilisk comes from mythology of Europe. (Read about it here.) They are a far mark different from what has evolved in the Dungeons and Dragons mythos, though. Here's the S&W (Complete, 3rd print, pg 100) stats:
AC: 4 
Attacks: Bite (1d10)
Saving Throw: 11
Special: Petrifying gaze
Challenge Level/XP: 8/800
Basilisks are great lizards whose gaze turns to stone anyone meeting its eye. (One way of resolving this: fighting without looking incurs a -4 penalty to hit.) If the basilisk's own gaze is reflected back at it, it has a 10% chance to force the basilisk into a saving throw against being turned to stone itself.
In AD&D, the basilisk has 8 legs, and its gaze reaches astral (turning the target to stone) and ethereal (simply killing the target).
Basilisks are a strange creature. There has been a lot of talk this week about dungeon ecologies (watch this video for more), and I would like to address it with the basilisk.
Basilisks are subterranean, and turn their potential meals to stone. I postulate, then, that they eat the stone. This makes basilisks a fantastic dungeon dweller. As a DM looking for visimilitude, it is unnecessary to have anything else near the basilisk's lair.
With this in mind, let's take a look at some interesting ways to use a basilisk in a game.
Basilisks pair well with almost any intelligent creature. In a lower level of Mord Mar, there are three trolls, with a trained basilisk. They keep its eyes covered unless in battle. The trolls try to maneuver the basilisk to the hallway, then remove the blindfold. The basilisk then charges whatever is moving that it can see, forcing saves against its gaze.
A pair of basilisks can be a deadly encounter, no matter the level of the characters. A mated pair of basilisks often hunt in the catacombs beneath a church. They know how to use angles to keep their prey within eyesight of at least one of them, and attack at perpendicular angles. Many adventurers have not returned after promising to rid the burial grounds of the threat.
A basilisk died in the Unholy Grounds. All creatures that die here return as undead. This undead basilisk is a ghoul, but has allied itself with several wraiths, as they seem immune to its gaze. This group terrorizes any living being that enters their floor of the dungeon.
The basilisk is not a boss monster. Its gaze attack means it is feared like one, though. When characters face a basilisk unprepared, there is often one or more casualties. Throw one (or more) at your players, and watch them squeal and run!
Artwork owned by Frog God Games, and used with permission.